1//===--- ASTImporter.h - Importing ASTs from other Contexts -----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines the ASTImporter class which imports AST nodes from one
11//  context into another context.
12//
13//===----------------------------------------------------------------------===//
14#ifndef LLVM_CLANG_AST_ASTIMPORTER_H
15#define LLVM_CLANG_AST_ASTIMPORTER_H
16
17#include "clang/AST/DeclarationName.h"
18#include "clang/AST/Type.h"
19#include "clang/Basic/SourceLocation.h"
20#include "llvm/ADT/DenseMap.h"
21#include "llvm/ADT/DenseSet.h"
22#include "llvm/ADT/SmallVector.h"
23
24namespace clang {
25  class ASTContext;
26  class Decl;
27  class DeclContext;
28  class DiagnosticsEngine;
29  class Expr;
30  class FileManager;
31  class IdentifierInfo;
32  class NestedNameSpecifier;
33  class Stmt;
34  class TypeSourceInfo;
35
36  /// \brief Imports selected nodes from one AST context into another context,
37  /// merging AST nodes where appropriate.
38  class ASTImporter {
39  public:
40    typedef llvm::DenseSet<std::pair<Decl *, Decl *> > NonEquivalentDeclSet;
41
42  private:
43    /// \brief The contexts we're importing to and from.
44    ASTContext &ToContext, &FromContext;
45
46    /// \brief The file managers we're importing to and from.
47    FileManager &ToFileManager, &FromFileManager;
48
49    /// \brief Whether to perform a minimal import.
50    bool Minimal;
51
52    /// \brief Whether the last diagnostic came from the "from" context.
53    bool LastDiagFromFrom;
54
55    /// \brief Mapping from the already-imported types in the "from" context
56    /// to the corresponding types in the "to" context.
57    llvm::DenseMap<const Type *, const Type *> ImportedTypes;
58
59    /// \brief Mapping from the already-imported declarations in the "from"
60    /// context to the corresponding declarations in the "to" context.
61    llvm::DenseMap<Decl *, Decl *> ImportedDecls;
62
63    /// \brief Mapping from the already-imported statements in the "from"
64    /// context to the corresponding statements in the "to" context.
65    llvm::DenseMap<Stmt *, Stmt *> ImportedStmts;
66
67    /// \brief Mapping from the already-imported FileIDs in the "from" source
68    /// manager to the corresponding FileIDs in the "to" source manager.
69    llvm::DenseMap<FileID, FileID> ImportedFileIDs;
70
71    /// \brief Imported, anonymous tag declarations that are missing their
72    /// corresponding typedefs.
73    SmallVector<TagDecl *, 4> AnonTagsWithPendingTypedefs;
74
75    /// \brief Declaration (from, to) pairs that are known not to be equivalent
76    /// (which we have already complained about).
77    NonEquivalentDeclSet NonEquivalentDecls;
78
79  public:
80    /// \brief Create a new AST importer.
81    ///
82    /// \param ToContext The context we'll be importing into.
83    ///
84    /// \param ToFileManager The file manager we'll be importing into.
85    ///
86    /// \param FromContext The context we'll be importing from.
87    ///
88    /// \param FromFileManager The file manager we'll be importing into.
89    ///
90    /// \param MinimalImport If true, the importer will attempt to import
91    /// as little as it can, e.g., by importing declarations as forward
92    /// declarations that can be completed at a later point.
93    ASTImporter(ASTContext &ToContext, FileManager &ToFileManager,
94                ASTContext &FromContext, FileManager &FromFileManager,
95                bool MinimalImport);
96
97    virtual ~ASTImporter();
98
99    /// \brief Whether the importer will perform a minimal import, creating
100    /// to-be-completed forward declarations when possible.
101    bool isMinimalImport() const { return Minimal; }
102
103    /// \brief Import the given type from the "from" context into the "to"
104    /// context.
105    ///
106    /// \returns the equivalent type in the "to" context, or a NULL type if
107    /// an error occurred.
108    QualType Import(QualType FromT);
109
110    /// \brief Import the given type source information from the
111    /// "from" context into the "to" context.
112    ///
113    /// \returns the equivalent type source information in the "to"
114    /// context, or NULL if an error occurred.
115    TypeSourceInfo *Import(TypeSourceInfo *FromTSI);
116
117    /// \brief Import the given declaration from the "from" context into the
118    /// "to" context.
119    ///
120    /// \returns the equivalent declaration in the "to" context, or a NULL type
121    /// if an error occurred.
122    Decl *Import(Decl *FromD);
123
124    /// \brief Return the copy of the given declaration in the "to" context if
125    /// it has already been imported from the "from" context.  Otherwise return
126    /// NULL.
127    Decl *GetAlreadyImportedOrNull(Decl *FromD);
128
129    /// \brief Import the given declaration context from the "from"
130    /// AST context into the "to" AST context.
131    ///
132    /// \returns the equivalent declaration context in the "to"
133    /// context, or a NULL type if an error occurred.
134    DeclContext *ImportContext(DeclContext *FromDC);
135
136    /// \brief Import the given expression from the "from" context into the
137    /// "to" context.
138    ///
139    /// \returns the equivalent expression in the "to" context, or NULL if
140    /// an error occurred.
141    Expr *Import(Expr *FromE);
142
143    /// \brief Import the given statement from the "from" context into the
144    /// "to" context.
145    ///
146    /// \returns the equivalent statement in the "to" context, or NULL if
147    /// an error occurred.
148    Stmt *Import(Stmt *FromS);
149
150    /// \brief Import the given nested-name-specifier from the "from"
151    /// context into the "to" context.
152    ///
153    /// \returns the equivalent nested-name-specifier in the "to"
154    /// context, or NULL if an error occurred.
155    NestedNameSpecifier *Import(NestedNameSpecifier *FromNNS);
156
157    /// \brief Import the given nested-name-specifier from the "from"
158    /// context into the "to" context.
159    ///
160    /// \returns the equivalent nested-name-specifier in the "to"
161    /// context.
162    NestedNameSpecifierLoc Import(NestedNameSpecifierLoc FromNNS);
163
164    /// \brief Import the goven template name from the "from" context into the
165    /// "to" context.
166    TemplateName Import(TemplateName From);
167
168    /// \brief Import the given source location from the "from" context into
169    /// the "to" context.
170    ///
171    /// \returns the equivalent source location in the "to" context, or an
172    /// invalid source location if an error occurred.
173    SourceLocation Import(SourceLocation FromLoc);
174
175    /// \brief Import the given source range from the "from" context into
176    /// the "to" context.
177    ///
178    /// \returns the equivalent source range in the "to" context, or an
179    /// invalid source location if an error occurred.
180    SourceRange Import(SourceRange FromRange);
181
182    /// \brief Import the given declaration name from the "from"
183    /// context into the "to" context.
184    ///
185    /// \returns the equivalent declaration name in the "to" context,
186    /// or an empty declaration name if an error occurred.
187    DeclarationName Import(DeclarationName FromName);
188
189    /// \brief Import the given identifier from the "from" context
190    /// into the "to" context.
191    ///
192    /// \returns the equivalent identifier in the "to" context.
193    IdentifierInfo *Import(const IdentifierInfo *FromId);
194
195    /// \brief Import the given Objective-C selector from the "from"
196    /// context into the "to" context.
197    ///
198    /// \returns the equivalent selector in the "to" context.
199    Selector Import(Selector FromSel);
200
201    /// \brief Import the given file ID from the "from" context into the
202    /// "to" context.
203    ///
204    /// \returns the equivalent file ID in the source manager of the "to"
205    /// context.
206    FileID Import(FileID);
207
208    /// \brief Import the definition of the given declaration, including all of
209    /// the declarations it contains.
210    ///
211    /// This routine is intended to be used
212    void ImportDefinition(Decl *From);
213
214    /// \brief Cope with a name conflict when importing a declaration into the
215    /// given context.
216    ///
217    /// This routine is invoked whenever there is a name conflict while
218    /// importing a declaration. The returned name will become the name of the
219    /// imported declaration. By default, the returned name is the same as the
220    /// original name, leaving the conflict unresolve such that name lookup
221    /// for this name is likely to find an ambiguity later.
222    ///
223    /// Subclasses may override this routine to resolve the conflict, e.g., by
224    /// renaming the declaration being imported.
225    ///
226    /// \param Name the name of the declaration being imported, which conflicts
227    /// with other declarations.
228    ///
229    /// \param DC the declaration context (in the "to" AST context) in which
230    /// the name is being imported.
231    ///
232    /// \param IDNS the identifier namespace in which the name will be found.
233    ///
234    /// \param Decls the set of declarations with the same name as the
235    /// declaration being imported.
236    ///
237    /// \param NumDecls the number of conflicting declarations in \p Decls.
238    ///
239    /// \returns the name that the newly-imported declaration should have.
240    virtual DeclarationName HandleNameConflict(DeclarationName Name,
241                                               DeclContext *DC,
242                                               unsigned IDNS,
243                                               NamedDecl **Decls,
244                                               unsigned NumDecls);
245
246    /// \brief Retrieve the context that AST nodes are being imported into.
247    ASTContext &getToContext() const { return ToContext; }
248
249    /// \brief Retrieve the context that AST nodes are being imported from.
250    ASTContext &getFromContext() const { return FromContext; }
251
252    /// \brief Retrieve the file manager that AST nodes are being imported into.
253    FileManager &getToFileManager() const { return ToFileManager; }
254
255    /// \brief Retrieve the file manager that AST nodes are being imported from.
256    FileManager &getFromFileManager() const { return FromFileManager; }
257
258    /// \brief Report a diagnostic in the "to" context.
259    DiagnosticBuilder ToDiag(SourceLocation Loc, unsigned DiagID);
260
261    /// \brief Report a diagnostic in the "from" context.
262    DiagnosticBuilder FromDiag(SourceLocation Loc, unsigned DiagID);
263
264    /// \brief Return the set of declarations that we know are not equivalent.
265    NonEquivalentDeclSet &getNonEquivalentDecls() { return NonEquivalentDecls; }
266
267    /// \brief Called for ObjCInterfaceDecl, ObjCProtocolDecl, and TagDecl.
268    /// Mark the Decl as complete, filling it in as much as possible.
269    ///
270    /// \param D A declaration in the "to" context.
271    virtual void CompleteDecl(Decl* D);
272
273    /// \brief Note that we have imported the "from" declaration by mapping it
274    /// to the (potentially-newly-created) "to" declaration.
275    ///
276    /// Subclasses can override this function to observe all of the \c From ->
277    /// \c To declaration mappings as they are imported.
278    virtual Decl *Imported(Decl *From, Decl *To);
279
280    /// \brief Called by StructuralEquivalenceContext.  If a RecordDecl is
281    /// being compared to another RecordDecl as part of import, completing the
282    /// other RecordDecl may trigger importation of the first RecordDecl. This
283    /// happens especially for anonymous structs.  If the original of the second
284    /// RecordDecl can be found, we can complete it without the need for
285    /// importation, eliminating this loop.
286    virtual Decl *GetOriginalDecl(Decl *To) { return nullptr; }
287
288    /// \brief Determine whether the given types are structurally
289    /// equivalent.
290    bool IsStructurallyEquivalent(QualType From, QualType To,
291                                  bool Complain = true);
292  };
293}
294
295#endif // LLVM_CLANG_AST_ASTIMPORTER_H
296